1. Field of the Invention
The present invention relates to an electrophotographic photosensitive member. More particularly, the present invention relates to an electrophotographic photosensitive member superior in sensitivity and potential stability.
2. Related Background Art
Recent electrophotographic photosensitive members comprising an organic compound as a main constituent have various advantages such as superior film-forming property, non-pollution, ease of manufacture, and so on, as compared with inorganic type photosensitive members. In particular, some lamination type photosensitive members are practically used which comprises a layer containing a material for generating electric charge on light irradiation (a charge-generating layer) and a layer containing a material for transporting the generated charge (a charge-transporting layer) because of their higher sensitivity and high-charge stability. Photosensitive members employing an azo pigment which is a typical charge-generating material were disclosed in Japanese Patent Application Laid-open No. 59-33445 and No. 60-111249. Such photosensitive members employing the azo pigment as the charge-generating material are not always satisfactory in sensitivity, residual potential, or stability in repreated use, and are limited in the range of selection of the charge-transporting material, thus not satisfying extensive requirement for electrophotographic processes.